No RCD = EICR fail ?

Risteard

Section62 said:

SusieT said:

...but an RCD would only trip its circuit and if I was stupid enough to somehow stick my finger in a live wire it should save me from a shock? 

An RCD working correctly should help reduce the risk of you receiving a fatal electric shock in some situations, but it shouldn't be relied on as a method of preventing electric shock because there is no guarantee it will work, or you might be unlucky and find yourself in one of the situations where an RCD won't trip even though it is working as designed.

Also they protect 95% of people 95% of the time. Even if operating correctly you still may die.

movilogo

grumbler said:

Well, the sketch makes very little sense. I guess the second CU is operated by the 'kitchen' MCB, not connected directly to 'AC'.

Not sure about the formalities, but if in the CU1 some MCBs, including the 'kitchen' one, are connected to 'AC' via an RCD, then all these circuits will be protected, including the CU2.

Yes, that's correct - CU2 is fed by Kitchen MCB. 

markin

You don't want the fridge turning off for another device tripping so both would need replacing or rcbos used.

grumbler

markin said:

You don't want the fridge turning off for another device tripping so both would need replacing or rcbos used.

So, you are suggesting rewiring the kitchen and creating a dedicated circuit for the fridge, aren't you? My small house, like many other houses, is on one RCD.

movilogo

markin said:

You don't want the fridge turning off for another device tripping so both would need replacing or rcbos used.

I won't mind  I lived in this house for decades without any issues and now just for letting I need to get EICR. So if just one RCD solves my problem then I'll go for that route. 

Risteard

movilogo said:

markin said:

You don't want the fridge turning off for another device tripping so both would need replacing or rcbos used.

I won't mind  I lived in this house for decades without any issues and now just for letting I need to get EICR. So if just one RCD solves my problem then I'll go for that route. 

It won't, because no-one can install one RCD for it.

grumbler

Risteard said:

movilogo said:

markin said:

You don't want the fridge turning off for another device tripping so both would need replacing or rcbos used.

I won't mind  I lived in this house for decades without any issues and now just for letting I need to get EICR. So if just one RCD solves my problem then I'll go for that route. 

no-one can install one RCD for it.

Why can't it be one RCD?

Risteard

grumbler said:

Risteard said:

movilogo said:

markin said:

You don't want the fridge turning off for another device tripping so both would need replacing or rcbos used.

I won't mind  I lived in this house for decades without any issues and now just for letting I need to get EICR. So if just one RCD solves my problem then I'll go for that route. 

no-one can install one RCD for it.

Why can't it be one RCD?

For numerous reasons which I already outlined in a post above.

grumbler

Risteard said:

grumbler said:

Risteard said:

movilogo said:

markin said:

You don't want the fridge turning off for another device tripping so both would need replacing or rcbos used.

I won't mind  I lived in this house for decades without any issues and now just for letting I need to get EICR. So if just one RCD solves my problem then I'll go for that route. 

no-one can install one RCD for it.

Why can't it be one RCD?

For numerous reasons which I already outlined in a post above.

OK, hopefully I am the only one who cannot make sense of them.

Risteard

grumbler said:

Risteard said:

grumbler said:

Risteard said:

movilogo said:

markin said:

You don't want the fridge turning off for another device tripping so both would need replacing or rcbos used.

I won't mind  I lived in this house for decades without any issues and now just for letting I need to get EICR. So if just one RCD solves my problem then I'll go for that route. 

no-one can install one RCD for it.

Why can't it be one RCD?

For numerous reasons which I already outlined in a post above.

OK, hopefully I am the only one who cannot make sense of them.

I would have thought it was reasonably self-explanatory with two of the reasons I mentioned:

* It doesn't mitigate the effects of a single fault causing loss of supply to the entire installation;

* An RCD should not have cumulative Earth leakage exceeding 30% of its nominal rating - in the case of a 30mA device this is merely 9mA of leakage. It is unlikely that you could guarantee this across an entire electrical installation.

But I am happy to clarify if you tell me which part(s) you don't understand.